Windows Vista only: Shadow Copies, an automated file version saver built into all copies of Windows Vista (and enabled by default), isn't a complete backup solution, but it could be a life-saver in certain situations. As The How-To Geek blog points out, however, it's pretty hard to find, let alone extract files from. Luckily, a forum member at the Geek's site has posted a complete tutorial on accessing and recovering previous file versions using the free utility ShadowExplorer. Using ShadowExplorer requires a good deal more clicking and searching than Apple's Time Machine, but it's a good solution for those "Oops, I forgot to back up ..." moments. Hit the link below for instructions and screenshots.